What are the types of rectal prolapse?

Generally, the classification of rectal prolapse is primarily based on factors such as the degree of prolapse, etiology, and disease course, and includes partial prolapse, complete prolapse, internal prolapse, and external prolapse. A detailed analysis is as follows:

1. Partial Prolapse

Partial prolapse, also known as mucosal prolapse, involves only the downward displacement of the rectal mucosa. The prolapsed tissue is usually short, generally less than 2–3 cm in length, pale red in color, covered with mucosal folds, and soft in texture. It may protrude through the anus during defecation but often spontaneously reduces afterward. There is typically no significant pain, though patients may experience a sensation of incomplete evacuation or minor mucus discharge.

2. Complete Prolapse

Complete prolapse refers to the downward displacement and protrusion of the full thickness of the rectal wall, and sometimes even part of the sigmoid colon. The prolapsed segment is longer, often exceeding 10 cm, appearing cylindrical or cone-shaped, with visible circular rectal mucosal folds, dark red in color, and firmer in consistency. It protrudes through the anus during defecation or increased intra-abdominal pressure and usually requires manual assistance to be reduced after bowel movement.

3. Internal Prolapse

Internal prolapse, also called occult prolapse, occurs when the rectal wall descends but does not protrude beyond the anal verge; instead, the displacement remains within the rectal lumen. Patients typically show no visible external signs of prolapse but may experience symptoms such as difficulty in defecation, increased frequency of bowel movements, mucus in stool, or a sensation of blockage during defecation. Diagnosis usually requires specialized examinations such as digital rectal examination, colonoscopy, or defecography.

4. External Prolapse

External prolapse refers to cases where the prolapsed rectal wall clearly protrudes outside the anus and can be directly observed. Any prolapse—whether partial or complete—that extends beyond the anal verge falls under this category. Patients can visually notice the prolapsed tissue outside the anus. Depending on severity, some cases reduce spontaneously after defecation, while others require manual reduction.

Understanding the classification of rectal prolapse helps clinicians develop targeted treatment plans. For example, early-stage partial prolapse may be managed by lifestyle modifications and medical therapy, whereas complete or severe external prolapse may require surgical intervention. Individuals experiencing abnormal bowel habits, anal heaviness, or symptoms suggestive of prolapse should seek timely medical evaluation to determine the specific type and initiate appropriate management early, preventing disease progression and improving quality of life.